Effect of Reactor Irradiation on the Tensile Strength of Uniaxially Oriented Polyethylene Terephthalate

Abstract

A series of uniaxially oriented polyethylene terephthalate fibers irradiated in a nuclear reactor have been investigated. On the basis of tensile studies the ultimate tensile strength is found to decrease as the dose of reactor irradiation increases. However, the ultimate tensile strength is found to increase when the degree of molecular orientation increases. But after the samples have received a relatively high dose of irradiation the tensile strength approaches practically zero. The x‐ray diffraction scans of the nonirradiated samples with low degrees of orientation indicate very little crystallinity, whereas the very definite diffraction peaks associated with the irradiated and oriented samples indicate a definite trend toward crystallinity.